ENV100Y5 Lecture Notes - Lecture 6: Plate Tectonics, Banded Iron Formation, Carbon Cycle

• School: UTM
• Department: Environment
• Course: ENV100Y5
• Professor: Barbara Murck

Document Summary

Everal h(cid:455)potheses have (cid:271)ee(cid:374) proposed to e(cid:454)plai(cid:374) life"s origi(cid:374) Heterotrophi(cid:272) h(cid:455)pothesis (cid:894)(cid:862)pri(cid:373)ordial soup(cid:863)(cid:895: life originated from inorganic chemicals in the ocean, first life forms used organic compounds for energy. Pa(cid:374)sper(cid:373)ia h(cid:455)pothesis (cid:894)(cid:862)seeds(cid:863) fro(cid:373) spa(cid:272)e(cid:895: microbes delivered to earth on meteorites, organic compounds found in meteorites. Chemoautotrophic hypothesis (ocean depths: life originated at deep-sea hydrothermal vents, first organisms were chemoautotrophs, does not use light energy, but chemical energy to make food. Fossil: a remnant of a long-dead organism, preserved in stone. Fossil record: gives information about the history of past life: species have come and gone, and old forms have changed into new forms throughout. Not all fossils are (cid:858)(cid:373)a(cid:272)rofossils(cid:859) or (cid:272)a(cid:374) (cid:271)e pi(cid:272)ked up like a di(cid:374)osaur (cid:271)oa(cid:374: chemical e(cid:448)ide(cid:374)(cid:272)e (cid:272)a(cid:374) sho(cid:449) that (cid:858)life (cid:449)as here(cid:859) Life played a central role in the evolution of earth systems. Life had two main influences on the chemistry of the atmosphere: build-up of oxygen, removal of carbon dioxide.